Design, synthesis and DNA binding activities of late first row transition metal(II) complexes of bi-functional tri- and tetratopic imines

A series of novel Co(II), Ni(II), Cu(II) and Zn(II) complexes of tri and tetratopic hydrazones have been prepared. Ligands (LH2)-H-1 and (LH2)-H-2 were synthesized by the condensation of 2-formylphenoxyacetic acid with 2-hydrazinobenzothiazole and 2-hydroxy-3-hydrazinebenzopyrazine, respectively. The prepared complexes were characterized by the analytical and spectral techniques. All the complexes were found to be monomeric in nature with octahedral geometry. Both ligands were found to be electrochemically active in the working potential range showing single electron transfer process attributed to the deprotonation of carboxylic group of the 2-formylphenoxyacetic acid. The potency of the ligand and its complexes as antimicrobial agents has been investigated and made to interact with Escherichia coli DNA to investigate the binding/cleaving ability by absorption, hydrodynamic and electrophoresis studies. (C) 2012 Elsevier B.V. All rights reserved.